Conventional cost counters of such type are comprised essentially of purely mechanical displaying and calculating sections for subtracting a consumed amount of money from a given preset amount. There are also cost counters of purely electronic construction having the same means as conventional electronic registers. Such electronic type counters can transmit data on one hand, but have disadvantages on the other hand.
In general, a cost counter user pays a certain amount of money to a collector who sets the amount into a balance meter. The cost counter calculates a balance amount at each use and may continue operation as long as the balance amount is surplus. For this reason, the balance data should not be varied or lost or permitted to disappear even when the counter is not used for a long period of time, or the power source is shutdown. With a purely electronic counter, for example, the balance data after occurrence of a power failure should be confirmed even if an electronic circuit appears not to be disturbed. In a conventional electronic cost counter, however, such the loss of balance problem due to power failure is difficult to solve.
For example, a counter utilizing a RAM (Random Access Memory) as a memory means cannot be protected from the power shutdown. In order to solve this problem, a postage meter as shown in Japanese Patent Publication 58-117089 utilizes a non-evaporative memory as a memory means for the balance data, while some counters employ a magnetic memory means. Even these means cannot completely protect the data from being lost, because an accident in a reading means for inner data or in a displaying means may disturb the data and prevent its confirmation.
With the purely mechanical counter on the other hand, the problem of retaining the data upon the event of the type of accident encountered in the electronic types of construction may be avoided. A balance-displaying section of a mechanical calculating mechanism is extremely complicated, requiring an extremely difficult developing and manufacturing effort. Further, in the mechanical type it is nearly impossible to transmit the inner data to an external instrument and hence it is usually unsuitable for use in a data-maintenance art which utilizes an external data-retaining system.
Accordingly, an object of the invention is to provide a cost counter with a cost meter capable of reading stored data, which has the ability of retaining data of a balance amount by means of a simple mechanism utilizing an electronic calculating circuit.
Another object of the invention is to provide a cost counter capable of recovering and confirming the stored balance data which has hitherto been lost in the conventional electronic system in case of non-use for a long time or an accidental power shutdown and of transmitting the data to an external instrument for ensuring the data maintenance which has not been achieved by the conventional mechanical systems.
A further object of the invention is to simplify the mechanism by using a microprocessor for calculation with various controls and by using an electronic memory as a main memory means.
A still further object of the invention is to enable data equivalent to the stored balance data to be displayed on a mechanical balance-displaying meter for confirming the data upon an accident.
A further object of the invention is to provide a cost counter having a function of reading the displayed data from the mechanical balance-displaying meter into a memory and recovering the data therein upon disappearance of the data from the memory.